There are a lot people working on the science of music and the brain.  I'm a big fan of Nina Krause at Northwestern University.  Here are some quotes from her that have really inspired me:

We've found that by playing music -- an action thought of as a function of the neocortex -- a person may actually be tuning the brainstem.  This suggests that the relationship between the brainstem and neocortex is a dynamic and reciprocable one and tells us that our basic sensory circuitry is more malleable than we previously thought."

“Music is a resource that tones the brain for auditory fitness,” Kraus adds. “We can see this in individual people, and their neural signature in response to sound just reinforces the idea that we are what we do. And you really do have to do it. It’s not a matter of listening. You’re not going to get fit watching spectator sports. It’s what we actively do that tunes our nervous system."

 Nina Krause, Northwestern University - Music Training 'Tunes' The Human Auditory System. Science Daily

Here's a link to a treasure trove of info about music and it's amazing and positive effects on the brain and being:
http://www.brainvolts.northwestern.edu/projects/music/index.php